CNN, the Atlanta-based global news network, announced Friday that it had fired an editor in its London bureau after other editors uncovered what an inside source at the network called an “insane” amount of plagiarized material in her work.

“CNN has discovered multiple instances of plagiarism by Marie-Louise Gumuchian, a former CNN news editor. She wrote frequently about international news, writing and reporting about Africa, Europe, and the Middle East from our London bureau,” the note said. “We’ve terminated Gumuchian’s employment with CNN, and have removed the instances of plagiarism found in her pieces. In some cases, we’ve chosen to delete an entire article.”

Gumuchian worked for CNN for only about six months, after spending the nine previous years of her career at the wire service, Reuters. Most of the instances of plagiarism in Gumuchian’s CNN work were lifted from Reuters articles, a source told the journalism institute Poynter.org.

“It’s kind of ballsy — don’t you think your old colleagues might look to see what you were doing at your new job?” Poynter‘s source wondered.

The initial instance of plagiarism was flagged during a routine editorial review at CNN on Thursday of last week. CNN editors then checked some of Gumuchian’s other pieces and found what a Washington Post source said were “two or three things” that raised suspicion.

That led to a more thorough examination of Gumuchian’s stories, using plagiarism-detecting software which uncovered an “insane” number of instances where Gumuchian had copied from other articles, mostly Reuters stories.

CNN found 50 articles by Gumuchian that contained copied material. The Post source said that those articles contained 128 passages copied without attribution from other sources.

Much of the copied passages were “background material” filled in by the CNN reporter with plagiarism from other stories.

CNN said it had deleted the plagiarism from Gumuchian’s stories. In some cases — seven, according to the Poynter source — the outlet deleted entire articles.

When Gumuchian was confronted about the plagiarism, “she didn’t have much to say,” according to the Post source.

“Trust, integrity, and simply giving credit where it’s due are among the tenets of journalism we hold dear, and we regret that we published material that did not reflect those essential standards,” said CNN editors in their note.